Method for preparing a flour tortilla

ABSTRACT

The present invention relates to a method for preparing a flour tortilla comprising
         providing a flour tortilla dough in a portion sufficient to prepare the tortilla;   applying a fatty substance to at least part of the surface of the dough portion; thereafter   forming the dough into a tortilla shape; and thereafter and baking the dough.       

     The invention further relates to a tortilla obtainable by such a method and to the use of a fatty substance to improve a property of a tortilla prepared using a fatty substance.

The invention relates to a method for preparing a flour tortilla(including whole wheat, multi grain), to a tortilla obtainable by such amethod and to the use of a fatty substance to improve a property of atortilla prepared using a fatty substance.

Flour tortillas are a unique baked product, made from cereal flour,usually maize or wheat.

Wheat flour tortillas are gluten structured, just like bread. Almost alltortillas are chemically leavened, baked quickly and cooled to ambienttemperatures in less than 15 minutes.

Flour tortillas have soft, silky, smooth texture, are opaque and fluffyand have excellent pliability; are resistant to cracking and have small,evenly distributed blisters. Blisters create desirable characteristicsin the final product, showing up as lightly browned spots on thesurface.

Flour tortillas are becoming increasing popular, for instance as asubstitute for bread, rolls and buns.

Flour tortillas can be made by making a dough from flour, fat and saltand water. Most large commercial tortilla manufacturers use thehot-press method of mixing, forming and baking to produce flourtortillas, e.g. as described in Bello, A. B.; Serna-Saldivar, S. O.;Waniska, R. D. and Rooney, L. W. Methods to prepare and evaluate wheattortillas, Cereal Foods World (1991)

In this method, a smooth dough comprising flour, water, fat, salt, andusually one or more ingredients selected from baking powder, yeast,preservatives, gums, reducing agents and emulsifiers is mixed to anextensible, elastic, non-sticky and relatively firm dough.

By optimally mixing and adding proper water levels a silky,smooth-textured dough, with many layers in the final product is formed.

Dough temperature also affects consistency, with lower doughtemperatures increasing water absorption. This leads to a softer finalproduct. The temperature may for instance be in the range of 27-38° C.The optimum temperature for flour-tortilla dough is usually 27° to 33.5°C.

After mixing, the tortilla dough is scaled to a desired weight, usuallyfrom about 30 to about 150 gram, e.g. about 40 to about 50 gram or about45 to about 48 gram, depending on the desired diameter for the tortilla,is rounded into a ball and is then allowed to rest (relax, proof),usually for about 5-15 minutes. Proofing the dough helps the pressingprocess. Insufficient relaxation can result in a translucent finishedproduct with less layering.

After resting, the dough pieces are placed under a hydraulic press thatis heated. The pressing process forms a thin skin on the surface of thetortilla, limiting the escape of steam and carbon dioxide during baking.This causes the tortilla initially to form small blisters or gas pocketswhich deflate upon cooling.

Baking is usually done in a conveyer oven that flips the tortilla overduring its journey through the oven. In particular, a specialized directgas fired slatted belt may be used. Baking time (oven dwell time) mayfor instance be approximately 30 seconds in a 190° to 235° C. oven. In aspecific embodiment, the oven temperature is 190-200° C. The tortillasare then cooled and packaged.

The over-all quality of tortillas, is determined by various properties.In particular tortillas having a reduced fat content may be consideredinferior to regular-fat tortillas (typically containing about 8 -12 wt.% fat, for instance 8-9 wt. % fat), but also for regular-fat tortillasit is desirable to improve one or more properties.

Relevant properties in particular include:

Folding: a low tendency to break on the seams upon folding the tortillais desired.

Breaking: it is desired that the tortilla shows good resistance againsttearing. E.g. low-fat tortillas tend to be torn apart at a lower tearingforce than regular tortillas.

Rolling: a good tortilla should be easily rollable, e.g. around a knowndiameter dowel, rod or stick, without showing substantial crackingand/or breaking. This is especially a challenge upon aging of thetortillas. Thus, it would be desirable to provide a tortilla that hasgood rolling properties. In particular it is desired to provide atortilla with good rolling properties for a prolonged period of time.

Springiness: Upon taking a low fat full tortilla in one hand andcrumpling or wadding it firmly, it is desirable that the tortilla‘springs back’ freely and unfolds completely without breaking.

Colour: a product with a substantially uniform (off-)white colour,wherein blisters are present is appreciated by many consumers. Theblisters show up as lightly browned spots on the surface. In particular,low-fat tortillas have a less off-white, more pale and less uniformcolour.

Layering/lamination: a layered structure of the tortilla is desired. Inparticular, low-fat tortillas tend to be less layered compared toregular tortillas.

Dryness: a tortilla should preferably have a not too dry mouthfeelConsumers recognize reduced fat and low fat tortillas as having a driermouthfeel than traditional full fat tortillas.

Size: The size (diameter) of conventional reduced fat tortillas issignificantly smaller than the size of regular-fat tortillas, of thesame weight. Low-fat tortillas of a specific weight may for instancehave a diameter that is less than 90% of the diameter of a regular-fattortilla of the same weight and apart from the fat having the samecomposition

Uniformity size/shape: Reduced fat tortillas tend to be less uniform inshape and size.

Stacking stickiness: It is desired that—when stacked and packaged—tortillas show no or a low tendency to stick to one another. Inparticular, upon aging the tendency to stick may increase. Inparticular, tortillas known in the art, made with vegetable oil insteadof solid shortening tend to stick more to each other upon prolongedshelf life. Also tortillas, known in the art, made with enzymes, such asbacterial or fungal amylases, tend to stick more to each other,regardless of shelf life.

Stack height: As a consequence of smaller diameters, the height of astack of, e.g., 10 tortillas is generally higher for reduced fattortillas than for regular fat tortillas; i.e. low fat tortillas arethicker than regular tortillas. This is unwanted due to negative effectson rollability, foldability and eating characteristics.

Opacity: Opacity is measured subjectively using a continuous scale. 100%is completely opaque (white) and 0% is completely translucent (notwhite). Ideally, translucency is eliminated since opacity is a desiredquality attribute.

It is an objective of the present invention to provide a novel methodfor preparing a flour tortilla, respectively a novel flour tortilla,wherein one or more of the above properties are improved compared to atortilla having the same composition, prepared with a known hot-pressmethod, such as described above.

It is in particular an objective of the invention to provide a novelmethod for preparing a flour tortilla, respectively a novel flourtortilla with a reduced-fat content, in particular with a fat content ofless than 5 wt. %. In a particularly preferred embodiment, the fatcontent is less than 4 wt. %, less than 3 wt. %, less than 2 wt. %, lessthan 1 wt. % or less, close to 0 wt. %, having one or more improvedproperties, compared to a known flour tortilla having the same fatcontent.

One or more other objectives which may be met in accordance with theinvention will be apparent from the description, below.

It has now been found that by treating a flour tortilla dough in aspecific way, before shaping the dough into the tortilla shape, it ispossible to provide a tortilla with one or more improved properties,compared to a conventionally prepared tortilla having the samecomposition.

Accordingly, the present invention relates to a method for preparing aflour tortilla comprising

-   -   providing a flour tortilla dough in a portion sufficient to        prepare the tortilla;    -   applying a fatty substance to at least part of the surface of        the dough portion;    -   forming the dough into a tortilla shape;    -   and baking the dough.

For an improved result, fatty substance is usually applied to at leastpart of the surface prior to forming the dough into a tortilla shape. Itis preferred if the fatty substance is applied to the entire surface ofthe dough ball.

The invention further relates to a flour tortilla obtainable inaccordance with the invention.

A tortilla obtained or obtainable in accordance with the invention inparticular shows one or more improved properties with respect to foldingcharacteristics, breaking characteristics, rolling characteristics,springiness, crust colour, layering/puffing, opacity, stackingstickiness and stack height compared to a tortilla made from a doughportion of the same dough (batch), to which surface of the dough portionno fatty substance has been applied. Preferably at least three, at leastfour, at least five, at least six or substantially all of saidproperties are improved.

In particular for a reduced-fat tortilla, such as a low-fat tortilla,diameter, thickness rollability, foldability, machinability, fluffiness,layering (smoothness), opacity and/or colour (whiteness) can beimproved. The diameter and/or thickness may in particular be improved by10% or more, e.g. by up to about 20%.

In particular for a regular-fat tortilla, diameter, foldability,rollability and/or thickness can be improved.

It has further been found that in a tortilla (obtained) according to theinvention shelf-life (stack sticking) may be improved.

In principle, a method of the invention can be used to prepare any typeof flour tortilla. The tortilla may be selected from no-fat tortilla's,reduced fat tortilla's, low-fat tortilla's and full-fat tortilla.

Full-fat tortillas usually have an ingredient-fat content of 5-20 wt. %,in particular of 6-20 wt. %, more in particular 8-20 wt. %

A method of the invention can be used for preparing regular-fattortillas, made from dough having a fat content) of about 8-12 wt. %(regular tortilla) or for tortillas, made from dough comprising lessthan 6 wt. % fat (reduced-fat tortillas), before applying the fattysubstance. The fat content, as used herein is the fat content based onflour weight, unless specified otherwise. The invention is in particularadvantageous with respect to providing a reduced-fat tortilla. The fatused when preparing the dough (i.e. mixed with the other ingredientsfrom which the dough is made) may also be referred to as “ingredientfat” to distinguish it from the fatty substance applied to the surfaceof a portion of the dough.

The ingredient-fat content of the dough for a low -fat tortilla (asdefined by the United States 21 CFR 101.62, 101.13 (1) (m)) may inparticular be less than 5 wt. % on flour weight or less than 3 g perserving of a 55 g tortilla. Preferably, the fat content is of about 3wt. % or less. More preferably the fat content is 2.5 wt. % or less. Ina specific embodiment, the fat content is 2.0 wt. % or less.

The dough may be prepared in a manner known per se, e.g. such asdescribed above.

Usually wheat flour is used for preparing the dough.

Flour usually comprises gluten and other protein(s) naturally present inthe flour. Optionally gluten and/or other protein is added. Usually theprotein content (including gluten) is at least about 7.5 wt. %. Usuallythe protein content (including gluten) is about 14 wt. % or less.Preferably the flour has a protein content of at least 9.5 wt. %, inparticular a protein content of 9.5-11.5 wt. %. With conventionallyprepared tortillas problems have been encountered with flour containingless protein or gluten yield tortillas that crack easily and split afterovernight storage. Flours with more than 11.5 wt. % gluten, however,produce doughs that take longer to mix and that require longer restingperiods before pressing and baking. It is contemplated that in a methodaccording to the invention, these drawbacks may be alleviated at leastto some extent.

Usually ingredient fat is present in the form of shortening(triglycerides, essentially solid at 20° C.) This improves machinabilityand reduces dough stickiness. High shortening levels also help preventcracking when the tortilla is folded or rolled. Lard and partiallyhydrogenated vegetable fats tend to make tortillas hard. Blending liquidoil with lard, other shortenings or partially hydrogenated liquidvegetable oils helps plasticize the tortilla. 100% vegetable oil (oilbeing defined as liquid at room temperature) is rarely used inconventional flour tortilla production due to excessive stackstickiness. But there is large interest from producers to use liquidoil; mainly with regards to trans-free requirements, costs, lack ofclogging and absence of the need for heating the fat before usage. Thus,the present invention offers an additional advantage in that asubstantial part or all of the shortening may be replaced by vegetableoil, whilst obtaining tortillas with an acceptably low stack stickiness.

An emulsifier (usually 0.3-0.8 wt. %, if present) can be present in thedough, for instance sodium-stearoyl-lactate (SSL). An emulsifier can beused to condition the dough, making it easier to handle and improvingthe finished texture. Mono- and diglycerides (e.g. distilled) can helpto reduce shortening levels, in order to achieve a similar shorteningeffect. These can be used to improve tearing quality and help preventtortillas from sticking to each other in the package. A monoglyceridemay be used to provide anti-staling qualities and improve shelf life. Upto 44% improvement in shelf life has been found possible upon using theco-blended product.

A leavening agent can be present, providing puffing during the bakingprocess, yielding a tender tortilla. Baking powder and leavening acidssuch as monocalcium phosphate (MCP), sodium aluminium phosphate (SALP)and sodium aluminium sulphate (SAS), sodium acid pyrophosphate (SAPP)may be used. Yeast may be used to provide the typical yeasty aroma andtaste, as well as for leavening.

One or more enzymes belonging to the group of amylases, xylanases,proteases, lipases and oxidases, can be added. The enzymes maycontribute to one or more desirable effects. Amylases have a positiveeffect on rollability and foldability, proteases have a positive effecton diameter and stack height. Xylanases and lipases have a positiveeffect on dough characteristics and on whiteness of the tortillas. Inconventional tortillas, enzymes can have a negative effect on tortillastickiness when used in suboptimal dosages or in suboptimalcombinations. The present invention is also useful to improve (reduce)tortilla stickiness, as a result of an adverse affect of an enzyme orcombination of enzymes.

A gum such as guar, carboxymethylcellulose, xanthan or gum arabic can beused to improve machinability, decrease dough stickiness, delay staling,improve rolling and folding properties, bind water, improve freeze/thawstability and decrease moisture loss. It is advised to add gum (usually0.1-0.5 wt. %, if present) during dry-blending to assure a homogeneousmix.

Starch can also add functionality to tortilla dough. Co-blendingunmodified pregelatinized starches, such as potato starch, waxy starch,high amylose starch (usually 5-15% based on flour weight, if present)with monoglyceride can improve machinability of a tortilla dough, thusimproving production capacity.

A reducing agent can be used to improve dough quality and reduce restingtime. L-cysteine, sodium bisulphite or sodium metabisulphite (usually10-40 ppm, if present) may be used improve machinability and decreaseelasticity.

An oxidizing agent such as ascorbic acid, azodicarbonamide or calciumperoxide may be used to improve mixing tolerance and doughmachinability.

Milk solids can be added, such as non-fat dry milk. Such ingredient canimprove crumb colour, flavour or dough handling. A concentration ofabout 0.75 wt. % milk solids is recommended.

A preservative can be added (usually 0.1-0.75 wt. %, if present), toinhibit mould growth after packaging. Sodium and calcium propionate,organic propionates, potassium sorbates, sorbic acid are in particularsuitable as tortilla preservatives.

If desired, a pH-regulator, typically an acid such as fumaric, adipic,citric, is added to control the final pH of the tortilla, which ispreferably 5.5 to 6.5 at 25° C.). pH can be determined by measuring thepH directly in the dough using a pH electrode. Alternatively, the pH inthe final product can be determined by homogenizing a tortilla piecewith fixed weight in water and measuring the pH using a glass electrodecoupled with a pH meter. A pH below this range may result in a lightercolour, while a pH above the range may result in a darker colour, abitter taste, more browning, a soapy mouthfeel or a limited mould freeshelf life.

As indicated above, at least part of the surface of the dough, isprovided with a fatty substance. As a fatty substance, in principle anylipid or emulsifier (which generally comprises a hydrophobic group, e.g.a fatty acid group, a hydrocarbon group or a group having a similar orhigher hydrophobicity) may be used that is allowed to be used in a foodapplication.

The fatty substance may be used as such or in combination with anothersubstance, for instance the fatty substance may be provided on acarrier, for instance (wheat) starch or flour. Preferably, the fattysubstance is used in combination with a drying agent. The drying agenthas a drying effect at the surface of the dough. As a drying agent, ingeneral hygroscopic substances, suitable for use in a food application,can be used. In particular, the drying agent may be selected from(wheat) flours and hygroscopic salts, such as a chloride or sulphatesalt of sodium, potassium, magnesium or calcium.

In a specific embodiment, also one or more enzymes are applied to andalso to at least a part of the surface of the dough. Such enzyme may beapplied together with the fatty substance, before the fatty substance orthereafter. The enzyme may contribute to one or more desirable effects,as mentioned above. ne or more enzymes belonging to the group ofamylases, xylanases, proteases, lipases and oxidases. Amylases have apositive effect on rollability and foldability, proteases have apositive effect on diameter and stack height. Xylanases and lipases havea positive effect on dough characteristics and on whiteness of thetortillas.

In an advantageous embodiment, the enzyme is applied together with thefatty substance.

In particular, the fatty substances may be selected from (triglyceride)oils, fat flours, emulsifiers, hardened fats, shortenings, emulsifiedshortenings, waxes, lecithins, and combinations thereof, which are knownfor use in the preparation of baked products, such as tortillas.

More in particular, the fatty substance or emulsifier may be selectedfrom the group of fatty acid monoglycerides, fatty acid diglycerides,fatty acid triglycerides, waxes, paraffins, sterols, sugar esters offatty acids, polyglycerol esters, polysorbates, lecithins, succinilatedand ethoxylated monoglycerides, stearoyl lactylates, mono- and diacetyltartaric acid esters of mono- and diglycerides (DATEM's) and fat flours.

Suitable triglyceride oils and fats which may be used include inparticular palm fat, palm oil, coconut oil, corn oil, cottonseed oil,canola oil, olive oil, peanut oil, safflower oil, soybean oil, sunfloweroil, butter, lard and tallow, and other fats and oils which are suitablefor use in food applications, e.g. oils from nuts or fruit seeds.Optionally a fraction of a (vegetable) triglyceride oil is used. Atriglyceride oil used as a fatty substance is optionally partially orfully hardened.

The emulsifier fatty substance may in particular be a glyceride or asugar ester of a fatty acid comprising one or more fatty acid residuechains having 2 carbon atoms or more.

Usually the fatty acid residue chains of a fatty substance used inaccordance with the invention have 26 carbon atoms or less, inparticular 22 carbon atoms or less. In particular for a low stickinessof the tortillas, it is preferred to use a fatty substance comprisingone or more long chain (having more than 12 carbons in the chain) orintermediate long chain fatty acid residues (having 8-12 carbons in thechain).

The fatty substance is preferably applied as a liquid, e.g. liquid oil,or a (fine) powder, crystal, granule or agglomerate, e.g. (fine, freeflowing) powdered fat, (fine, free flowing) powdered emulsifier, or(fine, free flowing) powder of fat on a carrier. This facilitates thefatty substance to be distributed evenly over the surface. Afree-flowing powdered fatty substance may for instance have beenobtained by spray drying or spray cooling.

In particular in case a powdered fatty substance is used, a fattysubstance may be selected having a relatively low melting range of20-40° C. This can be achieved by selecting fatty substances withintermediate long chain fatty acid residues (C8-C12) or fatty substanceswith high iodine number (which is a measure for the number of doublebonds in the fatty acid chain, or in other words a low degree ofsaturation); both leading to lower melting points.

The oil or free flowing powders may be applied onto the surface of thedough by spraying (oil, or sprayable liquid fats), or by dredging,sprinkling, or scattering.

Usually at least a substantial amount of the free flowing powders has aparticle size of less than 3000 μm; preferably less than 1000 μm., morepreferably less than 500 μm, more preferably less than 300 μm, morepreferable less than 100 μm and most preferably less than 10 μm. Asubstantial amount, as used herein in particular means at least 50%, inparticular at least 90%, more in particular at least 95%, preferably atleast 99% of the particles will pass a sieve with holes of said size.

The term “free-flowing” is used for a powdered material that is notsticky, and thus has no or hardly any tendency to clump or bridge inhoppers.

A solid fatty substance, in particular a solid triglyceride (mixture)may in particular be advantageous for maintaining a low stickiness, alsoafter a prolonged period of storage, compared to a liquid fattysubstance, such as a liquid oil.

Usually 10-100% of the surface of the surface is provided with the fattysubstance. In particular, at least 20%, at least 40%, at least 50% or atleast 75% of the surface may be provided with the fatty substance. Thiscan be achieved by spraying the liquid or powder over the dough piece,after which it is turned around and sprayed again. A good result can beachieved, also without fully covering the surface of the dough, inparticular by distributing the fatty substance essentially homogeneouslyover the surface.

Alternatively the fatty substance can be sprayed/sprinkled, dredged orscattered over the total dough piece just before moulding, dividing andshaping the small dough pieces which are fed into the tortilla machine.

The amount of fatty substance applied to said surface of the doughportion is usually at least 0.0001 g/g dough, in particular at least0.0005 g/g dough. Preferably the amount is at least 0.001 g/g dough,more preferably at least 0.002 g/g dough or at least 0.0025 g/gramdough.

The amount of fatty substance applied to said surface of the doughportion is usually 0.01 g/g dough or less, in particular 0.005 g/g doughor less. Such an amount is generally sufficient to improve one or moreproperties, whereas the increase in fat content in the final product islimited. Thus, the invention allows manufacture of tortillas which canstill be classified as low-fat tortillas, starting from low-fat dough.

A high level of fatty substance on the outside of the tortilla maycontribute to an extra improvement in the quality of the product. A highlevel of fat may lead to an increase in blister formation during bakingand an increase in tortilla stacking stickiness (compared to a method ofthe invention wherein a relatively low amount of fatty substance isused). For one or both of these reasons an amount of 0.0040 g/g dough orless, in particular of 0.0035 g/g dough or less may be preferred. Thefatty substance may be applied to the dough piece, before, during orafter resting, but in general before shaping (pressing).

The fatty substance may conveniently be applied in any way. In anembodiment, the fatty substance is applied by the providing plates of apress used to shape the dough with the fatty substance and then pressingthe dough. With this technique in particular it is easy to applyessentially the whole surface of the tortilla with fatty substance, thusproviding optimal coverage of the surface with fatty substance.

Advantageously, the fatty substance is sprayed as a liquid or powderonto the surface of the dough. Spraying is an advantageous technique,because it can easily be done in a continuous preparation process andallows a good distribution of the fatty substance on the surface. Also,this technique is advantage in that the contact-time of the fattysubstance with the (heated) pressing plate is kept at a minimum, therebysubstantially avoiding degradation of the fatty substance, in case it isheat sensitive. Further, it is easy to avoid contaminating the equipmentused for shaping (the press) with fatty substance.

In an embodiment, the fatty substance is applied by placing the doughportions on a surface provided with the fatty substance, for instance asurface on which the dough portions are allowed to rest. This is apreferred way of working when free flowing fat powder or emulsifierpowders are used since it will lead to more homogeneous distribution ofthe fat over the surface, especially when the dough pieces are turnedaround halfway during resting.

Also, this technique is advantageous in that the contact-time of thefatty substance with the (heated) pressing plate is kept at a minimum,thereby substantially avoiding degradation of the fatty substance, incase it is heat sensitive. Further, it is easy to avoid contaminatingthe equipment used for shaping (the press) with fatty substance.

The shaping is usually done after having the dough allowed to rest.Shaping is preferably done by pressing the dough portions under ahydraulic press. The press is preferably heated to between 175° and 235°C. The skilled person will know to determine a suitable pressure. Thepress usually exerts 750 -1,450 psi (5.2-10 Mpa) of pressure over theplates. Preferably the pressure is 200-3000 psi, more preferably500-2000 psi, most preferably 750-1450 psi, flattening the ball of doughinto the distinctive round, flat tortilla shape. Pressing time (pressdwell time) usually is between 0.9 and 1.5 seconds, preferably thepressing time is at least 1.1 sec. Preferably the pressing time is 1.4sec or less.

After shaping, the tortilla is baked. This can be done in a manner knownper se, e.g. as described above.

As indicated above, the invention further relates to a tortillaobtainable in accordance with the invention.

Fat contents may be chosen in a wide range, as indicated above. Usually,the tortilla has an added fat content of 20 wt. % or less. Inparticular, the added fat content may be 15 wt. % or less, 10 wt. %, or9 wt. % or less.

In an advantageous embodiment., the tortilla has a relatively low addedfat content, such as an added fat content of 5 wt. % or less, inparticular of 2.5 wt. % or less more in particular of 2 wt. % or lessbased on flour weight.

The invention will now be further illustrated by the following examples.

EXAMPLE 1

Tortillas have been prepared according to the following recipe andpreparation method:

% Ingredients Parts by weight (based on flour) Flour 1000 100 Water 54054 Salt 15 1.5 Shortening 90/20* 9/2* Baking powder: 2403 FY 20 2Fumaric acid 3 0.3 Sorbic acid 3 0.3 Calcium propionate 5 0.5 SSL 2.50.25 L-cysteïne 0.02 0.002 *90 parts for regular-fat tortilla; 20 partsfor low-fat tortillaBaking powder 2403 FY is a product from Fleischmann (USA) and contains:<40 wt % disodium pyrophosphate; <10 wt % calcium dihydrogen phosphate;<40 wt % sodium hydrogen carbonate.

Processing

-   Mixing: 2 min. slow 5 min. high speed with a McDuffy mixerDough    temperature: 30° C.-   Dough weight: 1500 g.-   Resting time: 2 min.-   Dividing/shaping: Automatic dividing/round up in 30 dough pieces of    50 g each with a W&P Rotomat GS50-   Resting time: 5 min. at room temp. on clothed plate.-   Lawrence Equipment semi automatic tortilla machine.-   Dwell time: 1,2 sec-   Dwell temp.: 400° F. and 415° F. bottom/top-   Baking temp.: between 400° F.-415° F., two top burners on-   Baking time ca.: ca 25 sec.-   Cooling: Ca. half an hour.-   Wrap: 10 pieces in a bag.-   The following examples of fatty substances have been evaluated-   Revel bake (fractionated, non hardened palm fat), Loders Croklaan,    Netherlands-   Monoglyceride (Abimono 90 HPF), Abitec, UK-   MCT (medium chain triglyceride) oil, Bergabest 60/40, Sternchemie,    Germany-   Vana Grassa (80% fractionated palm oil, melting point 44° C.).    Kievit, Netherlands-   Fat flour (50/50 blend of wheat flour with fat). Cereform, UK-   Mighty Soft (monoglyceride with high iodine number), Kerry    Ingredients, UK-   Various (50/50) combinations of the above.

The fatty substance have been applied (about 0.004 g/g dough or less)using one the following methods:

Spraying liquid

Dredging/sprinkling/scattering powder.

Dredging powder before dividing and shaping

Sprinkling free flowing fat powder on the plates on which the doughpieces are left for a dough rest and turning the dough pieces halfwaythe rest period.

Each of the tested fatty substance led to an improvement in one or moreproperties. In particular rollability, foldability, fluffiness, shape,opacity, stack stickiness and/or whiteness (as evaluated by a testpanel) were in general improved, in these experiments. Also, tortilladiameter was generally increased and stacking height was the same orincreased, compared to the conventional process.

Also shelf-life was in general improved. Shelf life stability wasevaluated using the rollability test during storage at 22°C. Tortillaswere wrapped around a dowel (1 cm diameter) and cracking and breakingwas evaluated by trained personnel using a scale from 1 (brokenimmediately, impossible to roll) to 5 (no cracks or breakage). Tortillashelf life was defined as the number of days the tortilla could berolled without substantial breaking; in other words, the time at whichthe rollability reached a score of 3.

The following table gives an indication of the improved results (averagefor all experiments).

Shelf Stacking Stack Life Type Rollability Foldability DiameterFluffiness Shape Opacity % height stickiness Whiteness (days) Regular7.5 7 17-18 7 7.5 75 0.9-1.0 7.5 7 9 tortillas Low fat 6.5 6.5 16-17 5 760 1.0-1.2 7 6 7 tortillas Tortillas 8-8.5 8-9 19-20 7.5-8.5 7-8 75-900.8-0.9 8-9 7-8.5 10-12 (regular or low fat) according to invention

More specifically, the following conclusions were drawn from theexperiments:

Intermediate chain fatty substances having a relatively low meltingtemperature or melting range showed in particular a positive effect onstack stickiness.

Monoglycerides showed in particular a positive effect on stack height.

The combination of fatty substance with a carrier (flour) showed inparticular a positive effect on diameter and stickiness.

It was further concluded that for fat powders the largest effects onexternal quality parameters (diameter, shape, opacity, blistering,colour) and on the structural quality parameters (rollability, etc. andshelf life) was achieved when the powder was essentially homogeneouslydistributed over the surface.

1-31. (canceled)
 32. A method for preparing a soft, rollable, wheatflour tortilla comprising providing a wheat flour tortilla dough in aportion sufficient to prepare the tortilla; applying a fatty substanceto all or at least part of the surface of the dough portion, wherein thefatty substance is a powder, granulate or crystal; thereafter formingthe dough into a tortilla shape using a hot press; and thereafter bakingthe dough.
 33. The method according to claim 32, wherein the tortillahas a fat content of at least 5 wt. %.
 34. The method according to claim32, wherein the tortilla is a full fat tortilla where the ingredient fatcontent is 20 wt. % or less, based on flour weight.
 35. The methodaccording to claim 32, wherein the amount of fatty substance applied tosaid surface of the dough portion is in the range of 0.0001 g/g dough to0.01 g/g dough.
 36. The method according to claim 32, wherein the amountof fatty substance applied to said surface of the dough portion is inthe range of 0.0015 g/g dough to 0.004 g/g dough.
 37. The methodaccording to claim 32, wherein the amount of fatty substance applied tosaid surface of the dough portion is in the range of 0.0025 g/g dough to0.0035 g/g dough.
 38. The method according to claim 32, wherein thefatty substance is applied by contacting the dough portion with asurface provided with the fatty substance.
 39. The method according toclaim 32, wherein fatty substance is applied by dredging, sprinkling orscattering a fatty substance powder over the dough portion.
 40. Themethod according to claim 32, wherein the fatty substance is appliedover the dough before dividing the dough into portions sufficient forpreparing the tortilla.
 41. The method according to claim 32, wherein atleast one fatty substance is used selected from the group ofmonoglycerides, diglycerides, triglycerides, waxes, paraffins, sterols,sugar esters of fatty acids, polyglycerol esters, fat flours,polysorbates, lecithins, succinilated monoglycerides, ethoxylatedmonoglycerides, emulsified shortenings, emulsifiers, such as DATEM orsodium-stearoyl-lactate (SSL), surfactants and combinations thereof. 42.The method according to claim 32, wherein the fatty substance is appliedas a fatty substance on a carrier, wherein the carrier is a powder or aground substance.
 43. The method according to claim 42, wherein thecarrier is a cereal flour or starch.
 44. The method according to claim42, wherein the carrier is calcium sulphate or calcium carbonate. 45.The method according to claim 32, wherein the fatty substance is appliedin combination with one or more enzymes selected from the group ofamylases, xylanases, proteases, lipases and oxidases.
 46. The methodaccording to claim 32, wherein the enzyme is applied encapsulated withinthe fatty substance.
 47. The method according to claim 32, wherein thefatty substance is applied in combination with a drying agent selectedfrom the group consisting of hygroscopic salts and flour.
 48. The methodaccording to claim 32, wherein the fatty substance is blended with aleast one component selected from the group consisting of drying agents,starches, anti-caking agents, emulsifiers, proteins or gums is appliedas spray dried or spray cooled free flowing powder.
 49. The methodaccording to claim 32, wherein the fatty substance is evenly distributedover the surface of the dough.
 50. The method according to claim 32,wherein the dough is made using flour having a protein content of about7.5 to about 14 wt %.
 51. The method according to claim 32, wherein thedough portion is baked for approximately 30 seconds at a temperature ofabout 190-230° C.